Tim Hunkin is a British inventor who recently made a solar powered sign that wiggles. His design for it was to run it by wind. His solar solution is a great read.
The letters of the sign sway up and down as if they are bobbing about on the waves. There’s nothing very complicated about the mechanism – its just one long crankshaft – but making it work by renewable energy has been less straightforward than I expected. I originally intended to make it wind powered. No electricity, just a geared down mechanical linkage to the crankshaft. I was worried about gales, so my first design was self furling (the propeller blades turn themselves out of the wind when it gets too strong). I was delighted to find I had a suitable worm gearbox and even a suitable propeller (from a petrol powered blower). It was a complete failure. I realised that what I had made was actually a very highly powered device for turning itself out of the wind, even in a light breeze.